

Introduction to CMMC 2.0 Personnel Security Controls
In today’s cybersecurity landscape, protecting sensitive government data is critical for organizations working with the Department of Defense (DoD). The Cybersecurity Maturity Model Certification (CMMC) 2.0 establishes a set of security controls that contractors must implement to safeguard Controlled Unclassified Information (CUI). Among these, Personnel Security Controls (PS.L2-3.9.1 and PS.L2-3.9.2) ensure that individuals handling CUI are properly vetted and that personnel actions maintain a secure work environment.
Personnel security is a foundational aspect of cybersecurity. Even the most advanced technical safeguards can be undermined if untrusted or inadequately screened personnel have access to sensitive systems and data. The Personnel Security (PS) domain in CMMC Level 2 is designed to reduce insider threats, prevent unauthorized access, and ensure that all employees follow security best practices.
This guide provides an in-depth breakdown of the Personnel Security Controls under CMMC 2.0, detailing what they entail, why they are important, and how organizations can comply effectively. Whether you’re a small business, a prime contractor, or a subcontractor working with the DoD, understanding and implementing these controls is crucial for securing contracts and maintaining compliance.
What Are the Two Key Personnel Security Controls in CMMC 2.0?
The CMMC 2.0 framework outlines two specific personnel security controls that organizations must follow:
- PS.L2-3.9.1 – Screen Individuals
- Requires organizations to conduct background checks and screenings to verify the trustworthiness of employees and contractors.
- PS.L2-3.9.2 – Personnel Actions
- Ensures that personnel actions, such as hiring, promotions, reassignments, and terminations, are handled securely to prevent unauthorized access to CUI.
Why Are Personnel Security Controls Important?
Failure to properly screen employees or manage personnel actions can lead to:
- Insider Threats: Malicious or negligent employees may intentionally or accidentally expose CUI.
- Unauthorized Access: Poor personnel management can result in former employees retaining access to sensitive systems.
- Regulatory Violations: Non-compliance with CMMC 2.0 can lead to penalties, contract loss, or reputational damage.
Implementing personnel security controls is not just about regulatory compliance; it’s about protecting national security and ensuring that only trusted personnel have access to critical systems and data.
Understanding PS.L2-3.9.1 – Screen Individuals
What Does “Screen Individuals” Mean in CMMC 2.0?
The PS.L2-3.9.1 – Screen Individuals control requires organizations to conduct background checks on individuals before granting them access to Controlled Unclassified Information (CUI). This ensures that employees, contractors, and third-party personnel handling sensitive government data are trustworthy and do not pose a security risk.
Personnel screening is a proactive measure designed to reduce insider threats, mitigate fraud risks, and prevent unauthorized access. It is a critical component of cybersecurity, as human vulnerabilities often lead to security breaches.
Who Needs to Be Screened?
Personnel screening should apply to:
- New Employees: Before granting system access, organizations must verify that an employee has no criminal background or other disqualifying history.
- Contractors & Third-Party Vendors: Any external party accessing CUI must undergo appropriate screening.
- Current Employees in Sensitive Roles: Employees moving into positions with access to CUI should be rescreened.
When Should Screening Occur?
Screening is not a one-time event but an ongoing security measure that should occur:
Best Practices for Personnel Screening
To effectively implement PS.L2-3.9.1, organizations should follow best practices for personnel screening. This includes:
1. Conduct Comprehensive Background Checks
A thorough background check should verify:
- Criminal History: Identify past offenses that may pose security risks.
- Employment History & References: Verify work experience and character references.
- Education & Certifications: Confirm academic and professional credentials.
- Credit Checks (If Applicable): Evaluate financial stability for roles handling sensitive financial data.
2. Use a Risk-Based Screening Approach
Different roles may require different levels of screening. For example:
3. Establish Clear Screening Policies
Organizations should document and communicate clear personnel screening policies, including:
- Screening requirements for different job roles.
- Compliance with federal and state employment laws.
- Privacy considerations and employee rights.
4. Partner with a Reputable Background Screening Provider
Using a third-party provider ensures accuracy and compliance with background check laws such as the Fair Credit Reporting Act (FCRA) and Equal Employment Opportunity Commission (EEOC) guidelines.
How to Implement a Compliant Screening Process
To stay compliant with CMMC 2.0, organizations should implement a structured screening process:
- Define Screening Policies: Outline the screening criteria for different roles and access levels.
- Obtain Employee Consent: Inform employees about background checks and obtain written consent.
- Perform Background Checks: Conduct checks through a compliant background screening provider.
- Review Results: Assess whether an individual is eligible for CUI access based on screening findings.
- Document Screening Records: Maintain records to demonstrate compliance in case of a CMMC audit.
- Reassess Periodically: Implement a rescreening policy for ongoing risk management.
Common Challenges & How to Overcome Them
While personnel screening is essential, organizations may face challenges when implementing this control. Below are common issues and solutions:
Final Thoughts on PS.L2-3.9.1 Compliance
Personnel screening is an essential component of CMMC 2.0 compliance and a critical security measure to protect sensitive government data. By implementing comprehensive screening policies, organizations can minimize insider threats, ensure the trustworthiness of employees, and maintain a secure work environment.
Understanding PS.L2-3.9.2 – Personnel Actions
What Are Personnel Actions in CMMC 2.0?
The PS.L2-3.9.2 – Personnel Actions control requires organizations to ensure that hiring, termination, and other personnel decisions do not compromise security. This control is essential for preventing unauthorized access to Controlled Unclassified Information (CUI) and minimizing the risk of insider threats.
Personnel actions cover a wide range of activities, including:
- Hiring new employees
- Changing job roles or responsibilities
- Granting or revoking access to CUI
- Terminating employees or contractors
By implementing structured personnel action policies, organizations can ensure that access to sensitive information is controlled at all stages of the employee lifecycle.
Why Secure Personnel Actions Matter
Poor personnel action management can lead to major security risks, including:
Ensuring secure personnel actions is a preventive measure that reduces these risks and keeps CUI protected.
Secure Employee Onboarding and Offboarding
Managing employee entry and exit securely is one of the most critical aspects of CMMC 2.0 personnel security compliance.
1. Best Practices for Secure Onboarding
When hiring new employees who will handle CUI, organizations should follow a structured onboarding process:
- Verify Personnel Screening Requirements – Ensure background checks (PS.L2-3.9.1) are completed before granting access.
- Assign Access Based on Role – Employees should only have access to necessary systems and information.
- Train New Employees on Security Policies – All personnel must be trained on CMMC 2.0 security practices.
- Document All Onboarding Activities – Maintain records of screening, access granted, and security training.
2. Best Practices for Secure Offboarding
The offboarding process is just as important as onboarding. Employees leaving an organization must not retain access to sensitive systems, ensuring no unauthorized access after departure.
- Immediately Revoke Access – Remove access to all systems, files, and physical locations.
- Collect Organization-Owned Devices – Retrieve laptops, ID badges, and authentication tokens.
- Monitor for Suspicious Activity – Audit the employee’s last login activities for potential data theft.
- Ensure Exit Interview Covers Security – Remind departing employees of security policies and legal obligations (such as NDAs).
Handling Insider Threats and Security Violations
Insider threats pose a significant risk to government contractors handling CUI. Organizations must take swift personnel actions if an employee is suspected of violating security policies.
1. Identifying Insider Threats
An insider threat is an employee, contractor, or business partner who intentionally or unintentionally exposes sensitive information. Common warning signs include:
- Unusual Data Access Patterns – Downloading large amounts of data without authorization.
- Disgruntled Behavior – Expressing dissatisfaction with the company and security policies.
- Bypassing Security Controls – Attempting to override security settings or gain unauthorized access.
- Leaving the Company Under Suspicious Circumstances – A departing employee attempting to take sensitive information.
2. Implementing Disciplinary Procedures
Organizations must clearly define how security violations will be addressed. A tiered response system is recommended:
How to Maintain Compliance with Personnel Actions
To ensure continuous compliance with CMMC 2.0, organizations must have policies in place for personnel security.
Develop Clear Policies for Hiring, Role Changes, and Terminations
All security policies should be documented, reviewed, and updated regularly.
Train HR and IT Teams on Security Responsibilities
HR and IT teams play a critical role in securely handling personnel actions. They must be trained in:
- Background checks
- Role-based access control
- Offboarding security procedures
Conduct Regular Audits and Compliance Checks
Organizations should periodically audit personnel actions to ensure proper procedures are followed.
Leverage Security Technology for Automation
Using Identity and Access Management (IAM) solutions helps automate the granting and revoking of system access when personnel changes occur.
Final Thoughts on PS.L2-3.9.2 Compliance
Compliance with PS.L2-3.9.2 – Personnel Actions is essential for protecting sensitive government data from insider threats and unauthorized access. By implementing secure hiring, access control, and offboarding policies, organizations can reduce risk, enhance security, and remain compliant with CMMC 2.0 requirements.
Key Takeaways:
- Personnel security is as important as cybersecurity. Even with strong firewalls, a malicious insider can expose CUI if not properly managed.
- Hiring and termination processes must be structured and secure. Every personnel action must be documented and aligned with security best practices.
- Ongoing monitoring and audits are necessary for compliance. Organizations must continually assess and refine their personnel security measures.

Conclusion – Staying Compliant with CMMC 2.0 Personnel Security Controls
Compliance with personnel security controls under CMMC 2.0 is essential for protecting Controlled Unclassified Information and ensuring that only trustworthy individuals have access to sensitive data. By implementing structured personnel screening and secure personnel actions, organizations can minimize security risks, prevent insider threats, and demonstrate compliance with government regulations.
Screening individuals through background checks helps identify potential risks before granting access to critical systems. Organizations should implement a structured screening process that includes verifying criminal history, employment records, and educational credentials. Periodic rescreening and continuous monitoring further strengthen security by ensuring that individuals with access to sensitive information remain trustworthy.
Managing personnel actions securely is just as important as screening. Organizations must follow strict procedures for onboarding, role changes, and offboarding to prevent unauthorized access to classified information. Immediate access revocation, security training, and ongoing monitoring should be integrated into personnel management processes to mitigate risks associated with insider threats and security breaches.
To maintain compliance, organizations should develop clear security policies, train HR and IT teams on proper security procedures, and conduct regular audits to ensure adherence to CMMC 2.0 requirements. Leveraging automated security solutions, such as identity and access management tools, can further streamline compliance efforts and reduce human errors.
Adopting these best practices not only ensures compliance with CMMC 2.0 but also strengthens an organization’s overall security posture. By taking personnel security seriously, businesses can protect government contracts, build trust with stakeholders, and contribute to the safeguarding of sensitive defense-related information.
Disclaimer: The information and recommendations provided in this article are for general informational purposes only. They are not intended as legal, compliance, or professional advice. Organizations should consult with their own legal, cybersecurity, and compliance professionals before implementing any strategies or recommendations discussed herein.